1. Field of the Invention
This invention relates to novel indazole derivatives which are useful in therapeutics. More specifically, this invention relates to novel indazole derivatives having valuable effects for relief of inflammation, analgesic activity and for suppressing digestive tract ulcers, a side effect caused by using acidic non-steroidal anti-inflammatory drugs.
2. Description of the Prior Art
Various experiments to obtain novel and useful anti-inflammatory drugs have been done by many researchers in the field of synthetic organic chemistry. Most of the experiments relate to the synthesis or testing of steroidal hormone compounds such as corticosteriods, and acidic non-steroidal substances such as phenylbutazon and indomethacin. However, both of the steroidal hormone compounds and the acidic non-steroidal substances have undesirable side effects. On the other hand, basic non-steroidal agents show almost no side effects such as digestive tract ulcers cause by the acidic non-steroidal compounds, in addition to the fact that they have the same anti-inflammatory effect and analgesic activity as the usual acidic non-steroidal compounds. As the basic non-steroidal compounds, 3-aminoindazole was first reported in Bamberger, Liebigs Ann., 305, 339(1899).
A 3-aminoindazole derivative whose condensed phenyl ring has a halogen group or a trifluoromethyl group as a substituent and whose nitrogen atom at the 1-position has a hydrogen atom, a methyl group or a phenyl group is described in U.S. Pat. No. 3,133,081. This patent discloses usage of these compounds as drugs having central nervous system activity, and as muscle relaxants, analgesics and tranquilizers. However, pharmacological data of the derivatives are not disclosed. Moreover, the compounds of U.S. Pat. No. 3,133,081 have never been actually used as medicines.
Silvest et. al., Arzneim-Forsch, 16, 59 (1966) report that 1-benzyl-3-(3-dimethylaminopropoxy)indazole hydrochloride is effective against primary inflammation. For example, benzydamine hydrochloride is actually used as a medicine.
U.S. Pat. No. 3,681,382 discloses other 3-aminoindazole derivatives wherein the hydrogen atom linked with the 1-position nitrogen atom is substituted by an aryl group and the 3-position is a substituted .omega.-aminoalkyl group or an .omega.-heterocyclic aminoalkyl group having 1 to 5 carbon atoms together with the nitrogen atom; or a substituted .omega.-aminoalkylamido group or an .omega.-heterocyclic aminoalkylamido group having 1 to 5 carbon atoms together with the nitrogen atom. The patent also discloses usage of antidepressants and anti-inflammatory drugs. However, pharmacological data are not disclosed in the U.S. patent. Moreover, these compounds have never been actually used as medicines.
Though some indazole derivatives are known as described above, the prior art fails to teach or suggests the indazole derivatives of this invention.